Reversible spray tip assemblies are known for use in high pressure, airless spraying. In such assemblies, an orifice tip is supported in a turret which may be rotated 180 degrees between spraying and cleaning positions and which is interchangeable with other turrets having orifice tips of different diameters and capacities for particular spray applications. For sealing the turret, a floating seal is provided which has a forward sealing face that conforms with the outer cylindrical contour of the turret.
While line pressure will force the floating seal into sealing engagement with the turret during high pressure spray operations, to prevent leakage during start up conditions an initial compressive loading must be applied to the seal. Such initial compressive loading typically is effected upon screwing a retainer nut of the assembly onto the barrel of a spray gun or like supply line with which the spray tip assembly is to be used. The tighter the retaining nut is screwed onto the spray gun, the greater the sealing forces that are transmitted to the seal, and in turn, to the turret. Secure engagement of the retaining nut onto the spray gun can cause the seal to exert such high forces against the turret, as to make it difficult to rotate the turret for a cleaning operation, or to remove and replace the turret. As a result, when securing the spray tip assembly onto the spray gun, the installer often turns the retaining nut with a wrench until it begins to feel tight, and then the turret is manually rotated. If the turret can be turned easily, the retaining cap can be tightened further to ensure secure engagement with the spray gun. If the turret is difficult to turn, the retaining nut is loosened. Such procedure is time consuming and the initial compressive loading of the seal against the turret is established by the subjective feel of the individual installer. Moreover, often optimum tightness cannot be easily achieved, and the installer must tightly screw the retaining nut on the spray gun and then later loosen it each time the turret is to be rotated and/or removed and replaced.